This application is unrelated to any other pending applications.
Field of the Invention
The present invention relates to the control of agricultural pests, especially during postharvest packaging, shipment, and storage.
The prior art in this field generally involves the use of large, fixed fumigation facilities that require consolidation of agricultural commodities for treatment, a process that is not only expensive but also a major bottleneck in the flow of agricultural products from field to market.
Prior art treatment for pest control also includes use of vacuum conditions to accelerate insect death during fumigation. However, prior art vacuum fumigation requires use of expensive vacuum chambers.
Hypobaric storage of agricultural commodities also is advantageous since it can retard spoilage of many perishable commodities, but it is also cost-prohibitive.
Therefore, the problem to be solved is how to create hypobaric conditions for boxed products that can make vacuum fumigation and hypobaric storage of agricultural commodities practical and economical.
The present invention is directed to a practical and economical apparatus and method to create vacuum (hypobaric) conditions for pest control and/or storage of agricultural commodities contained in cartons or boxes.
The process begins by forming a stack of cartons containing agricultural commodities such as fruit or vegetables. This stack can be placed on a pallet for ease of handling.
The stack is then covered with rigid or semi-rigid panels or sheets of wood, plastic or metal that are strong enough to resist bending when vacuum is applied.
The sheets are pressed directly against the outer surface of the cartons, forming a box or shell around the stack of cartons.
Next, the shell is covered with an impermeable envelope, made from plastic or other material, that can be sealed from the atmosphere.
The envelope has one or more inlets for fumigants or gases to enter or to be evacuated.
Vacuum conditions are created and maintained inside the envelope, which will result in negative pressure on the panels and inward pressure on all carton surfaces.
The inward pressure on the carton surfaces is distributed to the supporting matrix of the carton walls, thereby maintaining the integrity of both the carton stack as well as the individual cartons under vacuum conditions.
Pesticide gases may also be introduced inside the sealed envelope, either with or without vacuum conditions.
Finally, it is known that storing agricultural commodities under hypobaric conditions operates to extend shelf life.
An object and advantage of the invention is that it provides a practical and economical means to treat agricultural commodities for pests.
A major advantage of this invention is that it provides an alternative to expensive specialized facilities currently being used for pest control.
A further object of the invention is that it is portable and inexpensive, making it unnecessary to invest in or otherwise maintain large pest treatment facilities currently in use, and also making it ideal for small producers and those in developing countries.
A further object of the invention is that it permits effective, non-destructive application of vacuum conditions to crush-prone boxed commodities.
Yet another object and advantage is that the invention permits treatment for pests with or without vacuum conditions.
A still further object and advantage is that the invention provides for controlled atmosphere storage and/or shipment of commodities under hypobaric conditions.
Another advantage is that the invention reduces processing time of agricultural commodities, thus allowing such products to arrive at market more rapidly when compared to those commodities that are processed at large, fixed pest treatment facilities.
Finally, a major object and advantage of the invention is that it can be used with a wide range of fruits, vegetables and other commodities susceptible to pest damage which can then be shipped in hypobaric and/or low oxygen environments, thus retarding spoilage and preserving their freshness.
Other objects and advantages will become apparent from reading the detailed disclosure and specification below.